Abstract: The existing water evaluation and planning system (WEAP) models lack consideration of regional water allocation priorities. In this paper, an improved WEAP model is developed by integrating these priorities determined by water safety degree, and is applied to water resources allocation for Guangdong-Hong Kong-Macao Greater Bay Area. The effects of allocation schemes with different regional and industrial priorities are compared. The results show the water safety of each city in this area varies across regions and industries. Guangzhou, Shenzhen and Dongguan have lower degrees of domestic and industrial water safety. Under the premise of ecological basic flows guaranteed, an allocation scheme that considers regional and industrial priorities improves the satisfaction of domestic and industrial water uses in the key areas, resulting in more reasonable allocation. In the dry period, the water demands by Shenzhen and Dongguan cannot be satisfied, and the river and reservoir connections are essential to the Greater Bay Area. This study demonstrates both regional and industrial allocation priorities are key factors to consider in improvement of the WEAP model.

Key words: water allocation priority, water safety degree, water evaluation and planning system model, Guangdong-Hong Kong-Macao Greater Bay Area